I wouldnt do it, I particularly like a very old persian recipe I use a lot.
Apple cider vinegar, honey, mint leaves [fresh and slightly crushed. Peppermint teabags if that is all you can get. I say I much prefer fresh=)]
Take any onion, red white or yellow. Take them, and cut them into wedges and try to leave it so each wedge is still sort of connected at teh root end so they stay wedges, but if you would prefer to just slice them any old way, knock yourself out. [well maybe not, i hate concussions…]
Put everything in a jar and shake it up to mix in the honey, about 1 tbsp per cup, and about a good quarter cup of fresh mint leaves or 1 teabag of dried. Add the onions. I let them live in the fridge, but they dont suffer if you just leave the jar out - this is very common when we go camping. Takes overnight to essentially pickle the onions. I have never had them last longer than a couple of weeks so I dont know how it would work as a general storage thing, but onions last almost forever just hung on the leaves anyway=)
Interesting (?) little fact about onion and garlic, from Wikipedia:
Garlic has been regarded as a force for both good and evil. A Christian myth considers that after Satan left the Garden of Eden, garlic arose in his left footprint, and onion in the right.